Air suspension systems have steadily increased in popularity in all segments of the trucking industry because of their numerous benefits. A properly designed system reduces the shock and vibration transmitted to the truck and trailer from the wheels and road, thereby reducing maintenance costs by reducing the wear and tear on the equipment. The use of an air suspension system that can include one or more air springs and air bags provides an integrated shock and suspension system that automatically changes to match the load being supported by the suspension system.
One problem encountered by all truckers occurs in the clearing and raising of the landing gear prior to the attachment or detachment of the trailer to or from the truck. It is a common occurrence for the trucker to pull into the lot to attach a cargo-carrying trailer to the truck. The trucker will first back the rear end of the truck beneath the hook-up pin located on the underside of the front end of the trailer and then connect the air lines and the electrical cables to the trailer. Then the trucker will go to lift up the landing gear or landing stands only to discover that the previous driver had positioned the trailer higher than the rear of the truck the trucker is driving. The trucker must then unhook the air lines and electrical cables and pull the rear of the truck out from beneath the front end of the trailer so that blocks, boards or 4×4s can be placed on the ground for raising the rear end of the truck to the correct height for clearing the landing gear so that the trailer can be attached to the truck and the landing gear can be raised up. However, seldom is the first attempt successful, and it usually requires a number of attempts of the trucker backing onto the blocks, getting out of the cab and checking the alignment and positioning of the rear of the truck relative to the trailer, getting back in the cab and pulling forward, then getting out of the cab so that more blocks can be added or removed, before the rear of the truck is raised to the appropriate height for clearing and raising the landing gear and making the successful connection to the trailer. This is an arduous, time-consuming, exasperating task that often leaves the trucker in a foul mood prior to a long trip.
The prior art reveals a number of lifting and jack systems for raising and lowering vehicles, with a primary emphasis on automotive vehicles.
For example, the Hauser patent (U.S. Pat. No. 3,749,363) discloses a system of jacks for raising containerized cargoes supported on transportation trucks wherein one jack is mounted to each corner of the container and the jacks can be simultaneously or independently operated.
The Schapansky patent (U.S. Pat. No. 4,645,181) discloses a high performance air jack that includes a load engaging bracket mounted to the cylinder of the air jack, and air tools can be attached to and operated from the air jack.
The Mueller et al. patent (U.S. Pat. No. 4,993,688) discloses a pneumatic jack system for an automobile wherein pneumatic jacks are mounted to the front and rear suspensions both of which are operated from the same air reservoir tank.
The Guzman et al. patent (U.S. Pat. No. 5,465,940) discloses a pneumatic jack system that includes a pneumatic jack mounted to the suspension of an automobile and controlled by a control switch located in the vehicle interior.
The Pradel patent (U.S. Pat. No. 5,632,471) discloses an air suspension system for an automotive vehicle that includes at least four air springs connected to a reservoir with at least one of the air springs located within a cavity formed on the vehicle body.
The Mattera patent (U.S. Pat. No. 5,765,810) discloses a vehicle jacking system that includes a pair of air jacks mounted to both the front and rear axles operated by an air compressor and an electrical control panel within the vehicle.
Nonetheless, despite the ingenuity of the above devices, there remains a need for a lift system that can be integrated with and retrofitted to the existing air suspension system of a vehicle, with an emphasis on being integrated with tractor-trailers, for raising the rear of the truck to the height of the trailer to clear the landing gear and connect the truck to the cargo-carrying trailer.